cells

What are eukaryotic cells?

Plant and animal cells with nucleus and cytoplasm.

What are prokaryotic cells?

Bacterial cells without nucleus but with cell wall and plasmids.

How do cells divide in animal embryos?

To produce new cell types.

How do cells divide in mature animals?

To replace old and damaged cells.

What happens as a cell differentiates?

It acquires sub-cellular structures for specific functions.

What is differentiation?

When a cell becomes specialized for its job.

What are specialised cells?

Cells that perform a specific function.

What is mitochondria?

Where respiration takes place, energy is released

What is chloroplasts?

Contains chlorophyll to absorb light for photosynthesis

What is vacuole?

Filled with cell sap, important for keeping the cells rigid to support the plant

What is nucleus?

Controls all the cell activities. Contains genetic information

What is cell wall?

Made of cellulose that strengthens the cell and provides support

What is ribosomes?

Where protein synthesis takes place. All proteins needed in the cell are made from amino acids

What is cytoplasm?

Where most chemical reactions take place

What is cell membrane?

Controls what enters and leaves the cell

What is a nerve cell?

Carries electrical impulses around the body

What are dendrites?

Branch-like structures that make connections

What is an axon?

Carries the nerve impulse

What are nerve endings?

Carry impulses by chemical transmitters

What is a muscle cell?

Specialised to contract and relax

What are mitochondria?

Transfer energy needed for muscle contraction

What is glycogen?

Stored for respiration in muscle cells

What are the special proteins in muscle cells?

Slide over each other to make fibres contract

What is a sperm cell?

Male reproductive cell

What is the function of the tail in a sperm cell?

Helps the sperm move to the egg

What is the function of the acrosome in a sperm cell?

Stores digestive enzymes to penetrate the egg

What does the nucleus of a sperm cell contain?

Genetic information

What is a root hair cell?

Absorbs water and minerals in plants

What is the function of the large surface area in root hair cells?

To move water into the cell

What is the function of the large permanent vacuole in root hair cells?

To speed up water movement by osmosis from the soil to the cell

What is the function of many mitochondria in root hair cells?

To release the energy needed for active transport of mineral ions

What is a palisade cell?

Carries out photosynthesis in plants

What is the function of many chloroplasts in palisade cells?

To trap light for photosynthesis

What is the function of the large permanent vacuole in palisade cells?

To keep the cell rigid

What is the function of the cellulose cell wall in palisade cells?

To provide structure

What is a xylem cell?

Transports water and mineral ions up the plant from the root

What is the importance of xylem cells in plants?

Supporting the plant

What is the function of lignin in xylem cells?

Builds up the cell walls forming hollow tubes

What makes xylem cells strong and able to withstand the pressure of water moving up the plant?

The spiral and rings in the xylem

What is a phloem cell?

Transports food such as glucose or dissolved sugars made in photosynthesis around the plant

What is the structure of phloem cells?

They form tubes with special sieve plates that allow water carrying the food to move freely through the tubes

What is the function of companion cells in phloem cells?

To keep them alive as most internal structures are lost

What is the function of the mitochondria in companion cells?

To transfer the energy needed

What are the levels of organization in living things?

Cells, tissue, organ, organ system, organisms

What is muscle tissue?

Tissue that contracts and relaxes for movement

What is glandular tissue?

Tissue that secretes substances like enzymes and hormones

What is epithelial tissue?

Tissue that covers the outside of the body and internal organs

What is muscle tissue?

Tissue that contracts and relaxes for movement.

What is glandular tissue?

Tissue that secretes enzymes and hormones.

What is epithelial tissue?

Tissue that covers the body and organs.

What is the circulatory system composed of?

Heart, blood vessels (arteries, veins, capillaries)

What is the function of muscular tissue in the circulatory system?

To constantly pump blood and allow blood to be pumped at a high pressure in the arteries

What is the function of epithelial tissue in the circulatory system?

To provide a covering

What are the components of the respiratory system?

Lungs, trachea, bronchi, alveoli, diaphragm, ribs, intercostal muscles

What is the function of the diaphragm and intercostal muscles?

Used in breathing

What is the function of the epithelial tissue in the respiratory system?

Provides a covering

What is the function of glandular tissue in the respiratory system?

Produces mucus to trap dirt

What are the organs involved in the digestive system?

Mouth, oesophagus, stomach, pancreas, liver, small intestine, large intestine, rectum and anus.

What is the function of the muscular system in the digestive system?

Allows chewing, squeezes food down, churns food with digestive juices, and moves food.

What is the function of the epithelial system in the digestive system?

Provides a covering.

What is the function of the glandular system in the digestive system?

Produces saliva and enzymes, secretes hydrochloric acid and enzymes, secretes enzymes, and secretes bile to neutralize stomach acid and emulsify fats.

What is resolution?

Ability to distinguish between two points

How does resolution affect the image?

Shows detail and clarity

What is magnification?

Ability to make small objects seem larger

What is the difference between light and electron microscopes?

Light has lower resolution and magnification, electron has higher

What is the formula for total magnification?

Magnification of eyepiece lens x magnification of objective lens

what equation links actual size, image size and magnification?

actual size=image size/magnification

What are stem cells?

Undifferentiated cells that develop into different types of cells.

Where does cell division occur in plants?

Meristems.

What can cells of the meristems produce?

All types of plant cells at any time.

Where are the main meristems found?

At the tip of shoots and roots.

What can be produced using the areas of meristems?

Clones.

What are stem cells?

Undifferentiated cells that can self-renew and differentiate.

Why is self-renewal important for stem cells?

To prevent depletion of stem cell population.

Why is differentiation important for stem cells?

To replace used up, damaged or dead specialized cells.

What are embryonic stem cells?

Stem cells found in early human embryos with potential to develop into any type of cell.

What are adult stem cells?

Stem cells found in certain places such as bone marrow that can only turn into related cell types.

Where are embryonic stem cells found?

They are found in early human embryos.

Where are adult stem cells found?

They are found in certain places such as bone marrow.

What are adult stem cells used for in medicine?

Treating diseases

How are blood diseases treated using stem cells?

Bone marrow transplant

What can stem cells be used for in replacing old blood cells?

Generating new blood cells

What are embryonic stem cells?

Stem cells from early human embryos

What is the potential use of embryonic stem cells?

Replacing faulty cells in future

What is therapeutic cloning?

Making an embryo with same genetic info as patient

What are the benefits of stem cell research?

Treating serious conditions, studying cell division, growing new organs

What are the risks of stem cell research?

Viral infections, cancer cells, ethical objections

What is diffusion?

Spreading of particles from high to low concentration

How do substances move in and out of cells?

By diffusion

What type of molecules can move through diffusion?

Only small molecules like oxygen

What is net movement in diffusion?

Majority of particles moving

What is a partially permeable membrane?

One with small holes in it

What are the factors affecting the rate of diffusion?

Concentration difference, temperature, surface area

What is diffusion?

Movement of substances from high to low concentration

Where does oxygen diffuse into the blood?

Alveoli

Where are villi located?

Small intestine

What happens during photosynthesis?

Conversion of light energy to chemical energy

What happens during respiration?

Conversion of chemical energy to ATP

What is osmosis?

Movement of water from high to low concentration across a membrane

What is the role of a partially permeable membrane in osmosis?

Allows water to pass through but not solutes